Turning cranes



Nov. 18, 1958 T. FLADMARK 2,869,789

TURNING CRANES Filed May 21, 1956 I United Staes This invention relates to improvements in hydraulically operated cranes, intended especially for marine use, and particularly to cranes to be mounted in smaller and highspeed ships. Hydraulic operation of such cranes is, according to experience, reliable and cheap in upkeep. When oil under pressure is used as the power transmission means, the introduction through a central axis meets with diificulties which are avoided by the arrangement according to this invention, because the crane frame with the hydraulic motors and operating handles etc. may be mounted stationarily in the ships deck with directly connected feeding and outlet conduits for the medium under pressure, so that the only thing on the crane which is swinging is the cog platform with rim with outrigger or crane beam or boom and a member with two wire pulleys in the crane top. The principal novelty of this invention resides in said member. According to this invention said member and the pulleys in same are so turnably journalled that the wires from or to the pulleys run in the center line of the swivel of said member, so that the wires move down to their respective drums without rubbing each other during the swinging of the crane boom.

The arrangement is described more detailed hereinafter and is illustrated diagrammatically, reference being made to the annexed drawing, wherein Fig. 1 illustrates the crane in plan and,

Fig. 2 shows same in side view.

In the drawing letter A denotes the crane frame or mast with an hydraulically driven ring gear B, to which,

5 atent at M, is swingably attached a V-shaped arm or boom C. D denotes the turnable member in the crane top. In this member two wire pulleys E and F are so journalled at N and O that a portion of a hoisting wire G as well as a portion of the lift wire H from the pulleys E and F are located and operate in the centre line of the swivel or pivot P of member D, that is through the axis of swivel bolt T. 5 denotes the wire drums. K denotes the platform, about which the ring gear with the crane beam or boom rotate on a vertical axis and upon which the crane operator has his station to operate the crane by means or" operating members L,

I claim:

In a stationary turnable crane having a liftable and lowerable outrigger, particularly for use on ships, comprising a stationary crane mast having a fixed axis and having a platform mounted thereon, a rotatable cogged rim on said platform, a V-shaped boom attached to said rim so as to be turned therewith in a horizontal plane, the improvement comprising a pair of guide pulleys, a hoisting wire and a boom lift wire extending over said pulleys respectively, a turnable mounting member in which said pulleys are mounted, a vertically extending pintle attached to said mast and about which said mounting member is turnably mounted, a third guide pulley located above said pintle in a position to receive said boom lift wire from one of said first mentioned pulleys in a path extending in prolongation of the center line of said pintle, said boom lift wire passing first upwardly and over said third guide pulley, then downwards, whereas said hoisting wire passes directly downwards, all in such a manner that said wires cannot enter into contact with each other, when the mast is turned about the vertical axis of the crane.

References (Ii-ted in the file of this patent UNITED STATES PATENTS 1,018,529 Swensson Feb. 27, 1912 1,076,992 Obstler Oct. 28, 1913 1,856,907 Chapman May 3, 1932 FOREIGN PATENTS 10,713 Great Britain June 10, 1845 

